[PATCH] ASoC: Intel: sof_sdw: initialize ret in asoc_sdw_rt_amp_spk_rtd_init()

[PATCH] ASoC: Intel: sof_sdw: initialize ret in asoc_sdw_rt_amp_spk_rtd_init()

[Ethan Carter Edwards]

There is a possibility for an uninitialized *ret* variable to be
returned in some code paths.

Setting to 0 prevents a random value from being returned.

Closes: https://scan5.scan.coverity.com/#/project-view/63873/10063?selectedIssue=1627120
Signed-off-by: Ethan Carter Edwards <ethan@ethancedwards.com>
---
Would it potentially be better to remove ret entirely and just return 0
explicitly at the end of the function and directly return in the if
statements? I'm not sure.
---
 sound/soc/sdw_utils/soc_sdw_rt_amp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sound/soc/sdw_utils/soc_sdw_rt_amp.c b/sound/soc/sdw_utils/soc_sdw_rt_amp.c
index 0538c252ba69b1f5a24ba2de2a610b22d0c0665f..61a00a3548d85689c13e2d2a301da17a572e4a0e 100644
--- a/sound/soc/sdw_utils/soc_sdw_rt_amp.c
+++ b/sound/soc/sdw_utils/soc_sdw_rt_amp.c
@@ -190,7 +190,7 @@ int asoc_sdw_rt_amp_spk_rtd_init(struct snd_soc_pcm_runtime *rtd, struct snd_soc
 	const struct snd_soc_dapm_route *rt_amp_map;
 	char codec_name[CODEC_NAME_SIZE];
 	struct snd_soc_dai *codec_dai;
-	int ret;
+	int ret = 0;
 	int i;
 
 	rt_amp_map = get_codec_name_and_route(dai, codec_name);

---
base-commit: febbc555cf0fff895546ddb8ba2c9a523692fb55
change-id: 20250210-soc_sdw_rt_amp-e9c703ebe4dc

Best regards,
-- 
Ethan Carter Edwards <ethan@ethancedwards.com>

Re: [PATCH] ASoC: Intel: sof_sdw: initialize ret in asoc_sdw_rt_amp_spk_rtd_init()

[Mark Brown]

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On Mon, Feb 10, 2025 at 11:08:27PM -0500, Ethan Carter Edwards wrote:
> There is a possibility for an uninitialized *ret* variable to be
> returned in some code paths.
> 
> Setting to 0 prevents a random value from being returned.

That'll shut up the warning but is the warning trying to tell us that
there's a logic bug somewhere in the function and we're for example
forgetting to look at a return value in some path in the function?

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Re: [PATCH] ASoC: Intel: sof_sdw: initialize ret in asoc_sdw_rt_amp_spk_rtd_init()

[Pierre-Louis Bossart]

On 2/11/25 07:13, Mark Brown wrote:
> On Mon, Feb 10, 2025 at 11:08:27PM -0500, Ethan Carter Edwards wrote:
>> There is a possibility for an uninitialized *ret* variable to be
>> returned in some code paths.
>>
>> Setting to 0 prevents a random value from being returned.
> 
> That'll shut up the warning but is the warning trying to tell us that
> there's a logic bug somewhere in the function and we're for example
> forgetting to look at a return value in some path in the function?

The problematic code is this:

for_each_rtd_codec_dais(rtd, i, codec_dai) {
	if (strstr(codec_dai->component->name_prefix, "-1"))
		ret = snd_soc_dapm_add_routes(&card->dapm, rt_amp_map, 2);
	else if (strstr(codec_dai->component->name_prefix, "-2"))
		ret = snd_soc_dapm_add_routes(&card->dapm, rt_amp_map + 2, 2);
}

return ret;

I am not sure if it's possible that either the for_each does nothing or that the two branches are skipped, but certainly initializing the 'ret' value makes sense to me.

Bard, Shuming, what do you think?

Re: [PATCH] ASoC: Intel: sof_sdw: initialize ret in asoc_sdw_rt_amp_spk_rtd_init()

[Kees Cook]

On Tue, Feb 11, 2025 at 12:54:52PM -0600, Pierre-Louis Bossart wrote:
> On 2/11/25 07:13, Mark Brown wrote:
> > On Mon, Feb 10, 2025 at 11:08:27PM -0500, Ethan Carter Edwards wrote:
> >> There is a possibility for an uninitialized *ret* variable to be
> >> returned in some code paths.
> >>
> >> Setting to 0 prevents a random value from being returned.
> > 
> > That'll shut up the warning but is the warning trying to tell us that
> > there's a logic bug somewhere in the function and we're for example
> > forgetting to look at a return value in some path in the function?
> 
> The problematic code is this:
> 
> for_each_rtd_codec_dais(rtd, i, codec_dai) {
> 	if (strstr(codec_dai->component->name_prefix, "-1"))
> 		ret = snd_soc_dapm_add_routes(&card->dapm, rt_amp_map, 2);
> 	else if (strstr(codec_dai->component->name_prefix, "-2"))
> 		ret = snd_soc_dapm_add_routes(&card->dapm, rt_amp_map + 2, 2);
> }
> 
> return ret;
> 
> I am not sure if it's possible that either the for_each does nothing or that the two branches are skipped, but certainly initializing the 'ret' value makes sense to me.
> 
> Bard, Shuming, what do you think?

I'm just skimming through patchwork and this patch doesn't seem to have
made any progress. What're next steps?

-Kees

-- 
Kees Cook